#include <iostream>
#include <algorithm>
using namespace std;

int a[20]={12,15,15,20,20,20,23,34,35,37,
           40,40,40,40,45,50,50,55,60,70};
int n=20;
 

int main()
{
  int x;
  cin >> x;
  while(x>=0)
  { int* p = lower_bound(a,a+n,x);
    cout << p-a << endl;
    cin >> x;
  }
  
  return 0;
}
  


